hi i have as 87 IROC-Z 5speed 305

what im having trouble here is the cylinder head on the passenger side i am having trouble getting the exhaust manifold off. the accumutator is in the way and i wanted to know before i remove it. is there anything else i must remove along with the accumulator? so i know what tools i need to get. or is there any other angle i can tackle this job so i can get my heads machined.\

any suggestions would be great

thank you